In general, an air cleaner serves to purify indoor air containing fine dusts, various noxious gases, various germs, molds, viruses, etc., by using a purification medium. Such an air cleaner can be used through all seasons because it has various functions of removing unpleasant odors and small particles such as ticks, pollen and furs of pets, preventing an outbreak of disease due to an aerial infection, and so forth as well as its principal function of maintaining indoor air clean and pleasant.
Air cleaners can be largely classified into two types: dry type and wet type. Dry type air cleaners can be divided again into a filter type and an electric dust collection type.
Here, the electric dust collection type uses no filter, so it has a merit in that there is no need to replace filters. However, if dusts are accumulated on an electric dust collecting plate, purifying efficiency of the air cleaner will be deteriorated, and dust removing capacity thereof will also be undermined.
As for the filter type air cleaner, on the other hand, since various fine particles are captured while air passes through filters, the filter type air cleaner exhibits a high purifying efficiency, and thus is adequate for use in a season when yellow dust comes. However, since the filters need to be replaced periodically, maintenance cost thereof is high.
Meanwhile, a wet type air cleaner employs a method for making floating particles in suctioned air deposited in water by allowing the suctioned air to contact water. Though the wet type air cleaner has not been commonly utilized yet, it has many advantages in that it does not requires a replacement of filters and generates little noise, while providing a humidifying function as well. Thus, for children, its use is preferred. However, when using the wet type air cleaner, water should be replaced or replenished, which would be rather cumbersome.
There has been proposed a wet type air cleaner having a simple structure in which cleaning water is stored in a certain space, and a blower unit and a water spray unit are installed in a same space. One of such wet type air cleaners is disclosed in Japanese Patent Laid-open Publication No. 2000-334240, entitled “WET TYPE AIR CLEANER”.
The wet type air cleaner includes an air circulation passage through which air is introduced into the inside of the air cleaner and then is outputted to the outside after being purified. A reservoir containing therein liquid to be sprayed is formed in a part of the air circulation passage. The air cleaner further includes a blower unit for allowing the air to be circulated through the air circulation passage and a spray unit for spraying the liquid into a spray space in the reservoir.
The blower unit includes a fan for suctioning the air into the spray space and a motor for driving the fan. The spray unit includes a pump for pumping up the liquid from the reservoir and a nozzle for spraying the liquid into the spray space.
Further, the air supplied into the air circulation passage typically flows downward after being introduced into the reservoir from upside, whereas the liquid is sprayed upward from downside. Therefore, the air introduced into the reservoir is brought into contact with fine liquid particles sprayed by the nozzle, thereby allowing noxious substances in the air to be adsorbed by the liquid.
In the conventional wet type air cleaner as described above, however, the blower unit for circulating the indoor air and the spray unit for spraying the liquid are installed individually. Therefore, separate motors are required to operate the blower unit and the spray unit, respectively, which increases the number of components of the air cleaner, resulting in a high manufacturing cost. Further, since the water is sprayed through the nozzle against the inner surface of the spray space, a high level of noise is caused.
Besides, in the conventional wet type air cleaner, droplets adsorbing fine dust are discharged to the outside together with the air, thereby resulting in a poor purification efficiency and an unexpected high humidity. Moreover, the contact between the cleaning water and the air is insufficient, so that the purification ability thereof is deteriorated.